Zugzwang

A great example I love showing people is Alpha Zero's infamous "Immortal Zugzwang Game" against Stockfish [0]. Stockfish gets utterly annihilated in a trap that seemingly springs out of nowhere, though of course the reality is that Alpha Zero was actually really in control the entire time. [0] https://www.youtube.com/watch?v=lFXJWPhDsSY

In old-school chess AIs, zugzwang is also of interest because it can break null-move pruning[0], which is a way to prune the search tree. "Null move" just means "skip your turn", and the assumption that skipping your turn is always worse than the optimal move. But in zugzwang positions, that assumption is wrong, so you have to avoid doing null-move pruning. Stockfish's heuristic for "risk of zugzwang" is basically "only kings and pawns left over", alongside logic for "is null-move…

I like how this concept applies to decision-making outside of games in daily life. I've certainly been in various situations where a clear yes/no decision felt arbitrary or forced, yet waiting it out (a.k.a. not making a move) would simply bring clarity or eliminate the need for the decision altogether.

So you also read that cancer story...